Momentum distributions for correlated nucleons in spin-singlet channels

A new form for the universal momentum distributions for spin-singlet [Formula: see text] pairs is discussed. It allows to consider the contact formalisms for the corresponding two-nucleon momentum distributions in nuclei depending on both relative and center of mass momenta of the nucleon pair. It is shown that the nuclear contacts are very weakly dependent on the [Formula: see text] interaction model for the 3 He nucleus. Based on the developed formalism, the momentum distributions and [Formula: see text] ratio for [Formula: see text]C are calculated for several [Formula: see text] interaction models and compared with the existing experimental data.